Distribution of Chlorinated Hydrocarbon Pesticides and PCBs in the ...

were visible epontic algae in the June samples so that higher
organochlorine levels in particulates in June samples likely
reflect organochlorines associated with these organisms.
4.4 Water Properties
4.4.1 Water Structure
Water depths during the course of the study varied
between 150 and 340 m. This depth range encompasses the
Arctic surface water (0 - 200 m) and the upper part of the
Arctic intermediate water (200 - 900 m) (Coachman, 1969;
Kinney & Q., 1970). Salinity and temperature profiles for
each trip are shown in Figures 4.1 - 4.2. The general
features of the water column are fairly typical of those
observed elsewhere in the Polar Basin (Jones and Anderson,
1987). The upper 50 m is well mixed and has a low salinity
and temperatures near freezing. The low salinity of this
layer is due to river run-off, North Pacific influx through
Bering Strait and the seasonal melting and freezing of ice
(Aagaard & d, 1981). In August, 1986 surface water was
slightly fresher (S= 31.9 ppt vs 32.2 ppt in May) with the
upper 5m noticeably fresher and warmer presumably as a
result of ice melt. Since sampling was from the edge of the
island in August, the upper 45 m will have been influenced by
the proximity of the island and may not be representative of
general water properties elsewhere in this depth range.
Below the well mixed low salinity surface layer is a broad
halocline between the surface layer and warmer, more saline
intermediate water of Atlantic origin which has its core over
much of the Arctic Basin between 400 - 500 m (temperature
maximum). Temperatures increased with depth below about 100
m with water below approximately 280 m having temperatures
above O'C.
Nutrient concentrations were uniform in the upper 50 m
in both May and June. Concentrations of inorganic nitrate,